If you are planning a complete data platform upgrade, you should be planning on using Windows Server 2016 as your operating system (assuming you are planning on using Windows rather than Linux). Windows Server 2016 has a number of advantages over older versions of Windows Server, including higher license limits for memory, better networking and clustering support, and a longer remaining support lifetime (January 11, 2022 for mainstream support). Windows Server 2012 and Windows Server 2012 R2 will fall out of mainstream support on October 9, 2018, which is not that far away.
One potential issue with Windows Server 2016 is the fact that Microsoft is now using a core-based licensing system for that product. Microsoft requires a minimum of eight core licenses per processor and sixteen core licenses per server. This could potentially be a point of confusion and extra SQL Server licensing costs for some organizations.
Here is the scenario. Imagine that you have done your sizing analysis and calculations for SQL Server 2017 usage, and you have decided that a new two-socket server with two, quad-core Intel Xeon Gold 5122 processors will best suit your performance needs and budget requirements. That particular processor costs $1221.00 each.
Shon Smith, your well-meaning server administrator is aware of the new Windows Server 2016 licensing model, and he wants this new database server to actually have the sixteen physical cores that he was forced to buy Windows Server 2016 core licenses for. He also wants to minimize the hardware cost of this new server. Because of this, he decides to buy a two-socket server with two, eight-core Intel Xeon Bronze 3106 processors (which only cost $306.00 each). Shon has maximized his investment in those sixteen required Windows Server 2016 core licenses, and he has saved $1,730.00 on the hardware. But what has he done to you, the DBA?
First, this new database server now will require sixteen SQL Server 2017 core licenses instead of only eight. For SQL Server 2017 Standard Edition, this means a $14,872.00 increase in your SQL Server license costs, while SQL Server 2017 Enterprise Edition would cost $57,024.00 extra due to this hardware change. But you have twice as many physical cores, so that must be better, right?
Actually, not at all in this case. The Intel Xeon Bronze 3106 has a base clock speed of only 1.7GHz, with no Turbo Boost, no Hyper-Threading and an 11MB L3 cache. The Intel Xeon Gold 5122 that you specified has a base clock speed of 3.6GHz, a Turbo Boost speed of 3.7GHz, along with Hyper-Threading and an 16.5MB L3 cache.
The system you originally specified would have more than double the single-threaded CPU performance compared to Shon’s modified system. Your original system would also have more total CPU capacity than Shon’s modified system. The Intel Xeon Bronze 3106 is a terrible choice for SQL Server usage!
Keep in mind that most SQL Server instances only require Windows Server 2016 Standard Edition (rather than Datacenter Edition). Those sixteen required core licenses for Windows Server 2016 Standard Edition only cost $882.00 total, not each. This means that you should not let that required minimum Windows Server 2016 core license count sway your processor choice for SQL Server.
This exercise assumes that SQL Server 2017 licenses have the same pricing model as SQL Server 2016 licenses. It also uses a particularly bad processor choice by Shon, to illustrate the point. Using two eight-core Intel Xeon Gold 6144 processors would have given you much better performance and scalability (at a higher hardware cost) for that extra SQL Server license cost.
Additional Resources
My new Pluralsight course, SQL Server: Upgrading and Migrating to SQL Server 2016 has just been published. This is my eleventh course for Pluralsight, but the complete list of my courses is here.
Building on this online course is a new three day class, IEUpgrade: Immersion Event on Upgrading SQL Server, taught by myself and Tim Radney. The first round of this course will be taught in Chicago from October 11-13, 2017.
Finally, I will be presenting a half-day session called Migrating to SQL Server 2017 at the PASS Summit 2017 in Seattle, WA from October 31- November 3, 2017.
Here is a link to the complete series about upgrading SQL Server.